The field of this invention relates to a liquid level gauge and sampling device and more particularly to a liquid level gauge and sampling device of the type comprising a tube which is to be lowered into a reservoir, permitting the liquid to rise within the tube to the level of the liquid in the reservoir, closing the tube to prevent escape of liquid therefrom, and then withdrawing of the tube from the reservoir to determine the level of the liquid (or liquids) in the reservoir by observing the level of the liquid in the tube.
At times it is desirable to determine the quantity of liquid within a tank. For the most part, it is usually very difficult to determine the level of the liquid in a tank. Frequently, such tanks are buried in the ground or are so large that the level of liquid cannot be easily determined. A further complication is that frequently such tanks are cylindrical and are positioned on the side. Mathematically it is difficult to determine the quantity of liquid in such a tank.
A common usage of such tanks is in gasoline service stations. Usually tank measurements are taken at the end of each day and are recorded and corresponded to the amount of gasoline which is pumped each day. The normal prior art method of measuring the liquid in the tank is to use a wooden measuring stick which includes a measurement scale on the side thereof. However, at times it is difficult to accurately read the measuring stick, since the operator must look for the line between the wet and dry area of the stick. This is sometimes very difficult to determine especially if it is night time.
Additionally, it must be determined if there is any water in the tank. Water is heavier than gasoline and therefore will settle to the bottom of the tank. If it is known that the water in the tank has risen to an undesirable level, it can be removed.